1. Field of the Invention
The present invention relates to a staple gun and in particular to a staple gun.
2. Description of the Prior Art
Conventionally, there are known staple guns such as those using electric power or compressed air to inject a staple into a target object.
FIG. 8 shows a staple injection nozzle 1 for injecting a staple from a staple gun into a target object. This staple injection nozzle 1 has a nozzle body 2 protruding from the front portion of the staple gun. In this nozzle body 2, a staple injection path 3 is formed through which the stable is injected. The staple (not depicted) has a pair of pins to be struck into a target object and a linking portion connecting these pins. The pins are set in the staple injection path 3 in such a manner that the pins are directed toward the target object. The staple set in the staple injection path 3 is pushed forward from the rear end thereof by a staple driver.
The staple injection path 3 has an upper portion closed by a cover plate 4 that can be opened, enabling to remove a staple which has been bent or a plurality of staples which are jammed.
In order to fix the cover plate 4, protrusions 5, 5 are provided at the top of two sides of the nozzle body 2. Bearings 9, 9 protrude from a rear portion of the surface of the cover plate 4 having a pin 8 for receiving a hinge portion 7 of a lock lever 6, so that both ends of a band 10 are rotatably held at both ends of the lock lever 6.
The cover plate 4 is supported on stepped portions 11, 11 formed on the side walls of the staple injection path 3. With the lock lever 6 rotated around the pin 8 to be in a raised state, the linkage portion 12 of the band 10 is set over the protrusions 5, 5. Then, the lock lever 6 is rotated around the pin 8 to be set in a lowered state and the band 10 is in an expanded state, so that the linkage portion 12 of the band is fixed to the stepped portions 11, 11.
However, such a staple gun has a problem that when a staple is injected from the staple injection nozzle 1, a staple may be subjected to a force caused by shock of the staple driver or hardness of a target object, the force tending to open, i.e., remove the cover plate 4 from the nozzle body 2. Moreover, when a staple is jammed in the staple injection path 3, the cover plate 4 is subjected to a force to open the cover plate 4 and a large load F is applied from the cover plate 4 directly to the linkage portion 12 of the band 10. This causes plastic deformation of the linkage portion 12, thereby lowering the force to push the cover plate 4. Thus, the cover plate 4 begins to rattle, changing a staple injection orbit, which in turn easily causes a staple jam.
It is therefore an object of the present invention to provide a staple gun capable of suppressing rattle of a cover plate.